1. Field of the Invention
The present invention relates to a radio access system supporting multi-radio access technology (RAT) and, more particularly, to a method and the apparatus for transmitting and receiving data over two or more heterogeneous networks.
2. Related Art
In a conventional radio communication environment supporting two or more heterogeneous networks, although a terminal has capabilities to access multi-RAT, the terminal is unable to access the multi-RAT at the same time and transmit and receive data to and from the two or more heterogeneous networks at the same time.
That is, a conventional terminal supporting multi-RAT accesses any one RAT based on switching and transmits and receives data over one network. Accordingly, if a terminal having multi-RAT capabilities transmits and receives data over a specific network and transmits and receives data over a network different from the specific network, the transmission and reception of data over any one network is stopped.
Accordingly, in the prior art, a terminal having capabilities supporting two or more heterogeneous networks is able to perform communication by using different networks, but efficiency is limited because the terminal operates based on simple switching.
Furthermore, since different networks independently operate, an inefficient operation is performed from a viewpoint of the overall flow management of a terminal
For this purpose, a method by which a terminal with multi RAT capability can transmit and receive data through two or more heterogeneous networks (a first system and the second system), i.e., simultaneously through each network, has been defined.
However, it is necessary to consider the velocity of the multi-RAT mobile station (MS) when the multi-RAT MS connected to the first system tries to access simultaneously to the second system supporting a local area network.
A WLAN, which supports 802.11, is generally used to provide high rate data in narrow area. If the multi-RAT MS is moving very fast, the multi-RAT MS can pass through the narrow coverage of 802.11 quickly even though the multi-RAT MS has the ability to access both the two heterogeneous networks (e.g., 802.11/802.16). In this case, for communication of the multi-RAT MS, unnecessary second system management may be requested to the multi-RAT MS and ABS by data communication which establishes and releases connection to the system supporting 802.11.